1. Field of the Invention
This invention relates to a method of repairing a contact pin header connector employed to connect a plurality of elongate contact pins carried thereby with associated pin receptor connectors of a contact interlayered backplane and an apparatus for facilitating such repair.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a prior art header connector assembly 10 is seen carrying a plurality of elongate header contact pins 12 that are received within and extend through associated interlayered pin receptor connectors 14. The pin receptor connectors 14 are mounted within pin receptor holes 13 extending through a backplane 15 of a multiport telephonic switch or the like. The header connector assembly 10 includes a rectangular, insulating header body 16 with a contact wall 18 extending between a pair of opposed, spaced, generally rectangular legs 20 extending perpendicularly from opposite ends of the contact wall 18. The contact wall 18 has a plurality of pin mounting holes 22 within which an enlarged diameter section or shoulder 12A of the contact pin 12 is snugly received and frictionally held. The enlarged diameter section 12A of the pin 12 is located between an aft pin section 12B protectively positioned between the legs 20 and a forward, leading end section 12C which protrudes from a back side 15A of the backplane 15. Between the enlarged diameter section 12A and the leading end section 12C is a compliant contact section 12D.
The compliant section is located within the backplane 15 and makes electrical contact with conductive layers 24 imbedded within the backplane 15 at inner layer connectors 25 within the pin receptor connector 14. As seen in FIG. 3A, the compliant contact section 12D has an H-shaped cross section with two pairs of spaced arms 26 and 28 in opposed relationship with respect to one another. The arms 26 and 28 resiliently press against the inner sides of the pin receptor holes 13 and the interlayered connector 25 to endure good electrical contact.
In addition, when it becomes necessary to repair the header connector assembly 10 the H-shaped cross section of the compliant contact section 12D enables it to be distorted into a reduced cross sectional dimensional shape, as shown in FIG. 3B. With this reduced dimensional shape shown in FIG. 3B, the compliant contact section 12D is enabled to be inserted into an annular insulator 30 shown in FIG. 4.
The annular insulator 30 has an elongate cylindrical body 32 and an annular shoulder 34 mounted to and radially extending outwardly from one end of the elongate body 32. Adjacent the opposite end of the cylindrical body is a tapered, preferably truncated conical, wall 36 that slants inwardly in a direction extending toward the end 37 opposite from the end with the annular shoulder 34. Extending through the shoulder 34, the elongate cylindrical body 32 and the tapered wall 36 is an elongate, centrally located cylindrical bore 38. The bore 38 is sized to snugly receive the compliant section 12D after it has been distorted into the reduced dimensional shape shown in FIG. 3B.
In accordance with the known method of repair of the header assembly 10, a selected one of the contact pins 12 is first removed from both the pin receptor hole 13 in the backplane 15 and from the associated pin mounting hole 22 in the contact wall 18 of the header body 16. This is accomplished by firmly grasping the object, or target, contact pin 12 with a so-called signal pin extraction tool (not shown) and then hammering the extraction tool in a direction away from the header contact wall 18 with a slide hammer attached to a handle end of the pin extraction tool until the object pin 12 has been fully removed from both the backplane 15 and the header body 16. This is done while the header assembly 10 remains mounted to the backplane 15 with the remaining contact pins 12 still interconnected with the backplane 15 and the contact wall 18.
After the object contact pin 12 has been extracted, in accordance with the known method of repair, the pin mounting hole 22 is enlarged to first enable passage of a drill bit into drilling engagement with the associated pin receptor connector hole 13. Using the relatively reduced diameter drill bit, the associated pin receptor connector hole 13 is enlarged to a diameter slightly larger than the outer diameter of the cylindrical body 32 to enable receipt of the cylindrical body 32 within the enlarged pin receptor connector hole 13. However, the enlarged pin receptor connector hole 13 is smaller than the outer diameter of the annular shoulder 34 to block the annular shoulder 34 and thus the entire annular insulator 30 from passing entirely through the pin receptor hole 13. Then the empty pin mounting hole 22 from which the object contact pin 12 has been extracted is also enlarged with a drill to a diameter which is slightly larger than the outer diameter of the of the annular shoulder 34 of the annular insulator 30 to accommodate passage of the entire insulator 30 including the shoulder 34 through the enlarged pin mounting hole 22.
A replacement pin 12' is fabricated by distorting the compliant contact section 12D to reduce the cross dimensional dimensions of the compliant section 12D of a replacement pin 12', FIG. 5, from that shown in FIG. 3A to that shown in FIG. 3B. Preferably a new contact pin, other than the extracted contact pin 12 is fabricated to produce the replacement pin 12'. Alternatively, the object contact pin 12 that was extracted is fabricated to produce the replacement contact pin 12'. In any event, in accordance with the known method, the contact pin selected for fabrication into a reduced cross dimensional replacement pin 12' has its compliant contact section 12D reduced by forcing the selected contact pin 12 successively into a regressively, size-ordered series of four different sized holes in a No. 13 drill gauge, starting with the largest drill gauge hole and ending with the smallest sized drill gauge hole until the compliant contact section 12D has been progressively reduced with respect to its cross sectional dimension to that shown in FIG. 3B. This reduction in cross sectional dimension enables insertion of the reduced cross sectional compliant contact section 12D into the elongate bore 38 of the insulator 30, as shown in FIG. 5.
In accordance with the known repair method, the insulator is inserted through the empty, enlarged, header pin mounting hole 22, and the cylindrical body 32 is inserted fully into the empty, enlarged pin receptor hole 13 with the shoulder 34 in abutting relationship with the surface of the backplane 15 at the bottom of and within the enlarged pin mounting hole 22. The cross dimensionally reduced replacement pin 12' is then releasably grasped at the end of the elongate signal pin insertion tip tool. The pin insertion tip tool is then manually manipulated to maneuver the leading end section 12C through the empty enlarged pin mounting hole 22 and into the opening of the cylindrical bore 38 adjacent the shoulder 34 while seated in the bottom of the pin mounting hole 22 in abutting relationship with the backplane 15. A slide hammer is attached at an end opposite the end grasping the replacement pin and used to hammer the replacement pin 12' through the elongate bore 38 of the insulator 30 while held within the enlarged receptor pin hole 13 until the enlarged diameter section 12A is in abutting relationship with the shoulder 34, as shown in FIG. 5.
The desired end result of this process is the location of the replacement pin 12' in the bore 32 of the insulator 30 seated within the enlarged pin receptor hole 22 with the enlarged diameter section 12A in abutting relationship with the collar 34 and contained within the enlarged pin mounting hole 22 of the header connector contact wall 18, as shown in FIG. 5.
The difficulty with this process that has been observed in practice is that because of the relative fragility of the insulator 30, the requisite tight dimensional tolerances and the difficulty of maintaining proper co-alignment of the replacement pin 12' with the bore 38, the insulator 30 often are damaged in the process of inserting the replacement pin 12' fully into the bore 38. For example, the cylindrical body 32 of the insulator 30 breaks away from the shoulder 34 when the replacement pin 12' is inserted into the insulator 30.